Real-world efficiency data
EV Range Estimator
Based on real-world fleet efficiency data — not EPA lab results. Enter your conditions and battery degradation to see what you'll actually get on a cold UK morning, a motorway run, or a summer holiday.
Quick scenarios
Your EV
Driving conditions
Estimated range
≈ 260 Wh/mi · 75 kWh baseline assumed
Range impact by factor
Baseline ≈ 260 Wh/mi real-world efficiency. Typical real-world estimates from third-party fleet & benchmark data — not official EV or lab figures. Results vary with driving style, tyres and conditions.
Cold weather in the UK
At 0°C, expect 15–20% less range from battery chemistry alone. With the heater on, add another 10–20%. Real losses in a UK January can reach 35–40%. Teslas with heat pumps (Model 3/Y from late 2020) handle cold significantly better than older resistive-only heaters.
Speed is the biggest drain
Aerodynamic drag increases with the square of speed — going from 60 to 70 mph uses roughly 20% more energy per mile. On a UK motorway at 70 mph you'll see around 94% of the 65 mph baseline. Push to 80–85 mph and that drops to 75–81%. Cruise control at 60–65 mph is the sweet spot.
Battery degradation
Tesla batteries typically lose 10–15% capacity after 5 years and 150,000+ miles. LFP packs (Model 3/Y RWD) degrade less than NCA/NMC. You can find your car's current degradation via the TeslaBatteryCheck tool or by checking rated vs. actual range in your Tesla app.
Don't know? Check yours →About these estimates
Wh/mi efficiency figures are derived from TeslaFi fleet telemetry (200M+ miles), Recurrent Auto fleet data, and Bjørn Nyland benchmark tests. They reflect typical real-world driving at 65 mph — not EPA lab conditions. Individual results vary with driving style, tyre pressure, and road conditions.
Why real-world range differs from WLTP and EPA figures
Every EV sold gets a headline range figure from a standardised lab test — WLTP in Europe and the UK, EPA in the US — run at controlled speeds and temperatures so buyers can compare models on equal terms. Neither test is designed to predict what you'll actually get on your commute. WLTP figures tend to run 10–20% ahead of real mixed driving for most brands, whether that's a Tesla, a BMW or a Škoda, while EPA figures are generally closer to real-world but still assume mild conditions and moderate speeds. The gap isn't a fault with any one manufacturer — it's built into how lab-cycle testing works, which is why a real-world estimator using actual fleet efficiency data gets you much closer to what you'll see on your own dashboard.
How speed, temperature and HVAC change your range
Speed is the single biggest lever — aerodynamic drag rises roughly with the square of your speed, so pushing from 60mph to 80mph on the motorway can use 30–40% more energy per mile, regardless of make. Outside temperature is the second biggest factor: cold weather can cut range by 10–30%, mostly from cabin heating and battery conditioning rather than the cold itself affecting the cells. Heavy use of air conditioning in hot weather has a smaller but still noticeable effect, typically 5–15%. Terrain, tyre size, and how many people and how much luggage you're carrying all add smaller adjustments on top — which is why the calculator above lets you tune each one individually rather than applying one blanket estimate.
Winter driving tips to protect your range
- Precondition while plugged in: warm the cabin and battery from the mains, not the battery, before you unplug.
- Use seat and steering wheel heaters: they use far less energy than heating the whole cabin's air.
- Keep tyres at the recommended pressure: cold weather drops tyre pressure, which increases rolling resistance.
- Charge to a higher percentage before long winter trips: a wider buffer covers the extra energy cold weather uses.
- Let navigation trigger fast-charger preconditioning: most EVs will warm the battery automatically en route to a rapid charger, which also improves winter charge speed.